Segment Information - Net Sales (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018
Segment Reporting Information [Line Items]
Net sales	$ 4,228	$ 4,596	$ 8,386	$ 8,800
Intersegment Eliminations
Segment Reporting Information [Line Items]
Net sales	(64)	(91)	(131)	(174)
Americas \| Operating segments
Segment Reporting Information [Line Items]
Net sales	1,915	1,941	3,850	3,727
EMEA \| Operating segments
Segment Reporting Information [Line Items]
Net sales	1,778	2,056	3,418	3,909
Asia \| Operating segments
Segment Reporting Information [Line Items]
Net sales	$ 599	$ 690	$ 1,249	$ 1,338

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130543-203045

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130539-203045

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130545-203045

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